The related function enum2str returns the value of a Label property from one element on the enum. The value returned by enum2str function can be the input for the _type parameter of the str2enum function.
An appropriate value for the _text parameter is enum2Str(BankAccountType::SavingsAccount).
Each element of an enum has a Name property and a Label property. In a fresh install of Microsoft Dynamics AX, the Name values are almost always English words. In the English edition of Microsoft Dynamics AX, the Label property value is almost always identical to the Name value. But in the non-English editions the Label values are localized, and therefore do not match the Name values.